// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Icon System base module.
*
* @module core/icon_system
* @copyright 2017 Damyon Wiese
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
import config from 'core/config';
/**
* Icon System abstract class.
*
* Any icon system needs to define a module extending this one and return this module name from the php icon_system class.
*
* @class core/icon_system
*/
export default class IconSystem {
/**
* A Promise which resolves to the Icon System instance.
*
* @private
* @var {Promise<IconSystem>}
*/
static iconSystemInstance = null;
/**
* Factory method to fetch the Icon System currently in use.
*
* @returns {Promise<IconSystem>}
*/
static async instance() {
if (this.iconSystemInstance) {
return await this.iconSystemInstance;
}
this.iconSystemInstance = (async () => {
const SystemClass = await import(config.iconsystemmodule);
const instance = new SystemClass();
if (!(instance instanceof IconSystem)) {
window.console.error('Class is not an IconSystem', SystemClass);
throw Error(`Invalid icon system specified ${config.iconsystemmodule}. Class is not an IconSystem.`);
}
return await instance.init();
})();
return await this.iconSystemInstance;
}
/**
* Initialise the icon system.
*
* @return {Promise<IconSystem>}
*/
init() {
return Promise.resolve(this);
}
/**
* Render an icon.
*
* The key, component and title come from either the pix mustache helper tag, or the call to templates.renderIcon.
* The template is the pre-loaded template string matching the template from getTemplateName() in this class.
* This function must return a string (not a promise) because it is used during the internal rendering of the mustache
* template (which is unfortunately synchronous). To render the mustache template in this function call
* core/mustache.render() directly and do not use any partials, blocks or helper functions in the template.
*
* @param {string} key
* @param {string} component
* @param {string} title
* @param {string} template
* @returns {string}
* @method renderIcon
*/
// eslint-disable-next-line no-unused-vars
renderIcon(key, component, title, template) {
throw new Error('Abstract function not implemented.');
}
/**
* Get the name of the template.
*
* @returns {string}
* @method getTemplateName
*/
// eslint-disable-next-line no-unused-vars
getTemplateName() {
throw new Error('Abstract function not implemented.');
}
}